Such gas cylinders, as a kind of plunger cylinder, can be advantageously used as an energy storage cylinder in devices for energy recovery, among other things. As is disclosed by way of example in DE 10 2008 034 582 A1, in such applications, the piston rod of the gas cylinder is connected to a movable element of an associated work tool. The movable element may be the boom of an excavator or of a machine for material handling or the like, for example. When lowering the movable element, the potential energy of the movable element and the load connected thereto is stored by the gas cylinder to provide at least partial compensation for the respective equipment weight when the movable element is raised again.
In the case of the higher pressures prevailing in the pressure chamber during operation, sealing the gas pressure against the ambient air is very difficult, even in the case of a working gas having relatively large molecules such as N2. Preventing gas losses with conventional sealing systems is scarcely possible.